Geological Wonder of the World
Geologically Devil's Lake is one of the wonders of the world. At the dawn of the earth's history there were no rivers or lakes or bluffs in the Baraboo region, the ocean or an inland sea covering all the land. At the bottom of the sea were the Archean or igneous rocks, the oldest formation known to geology. Upon these rocks the sand was piled a mile deep, the sand at a later time being changed into sandstone and still later metamorphosed into the hard quartzite which towers high in the bluffs. Resting upon the beds of sand were deposits of clay which changed to slate, limestone which became dolomite, and iron which remained in its elemental state.
Balance Rock, View of Devil's Lake, Stone Face
Later there was a mountain making movement of the earth and there appeared peaks as lofty as those in the Alps or Rockies. The once horizontal beds of sand, clay, limestone and iron were uplifted and folded in the process, the layers at the lake being inclined about fifteen degrees as seen along the East Bluff. The Baraboo Bluffs are among the oldest formed things on the globe—older than the Rockies or Alleghenies, older than a pound of coal on the earth, older than any tree or bird or beast that ever lived.
There was a long period of erosion and a river cut a gorge through the range where the lake is now located.
In Paleozoic times the sea returned again, the tops of the bluffs stood as islands above the waves, the loose rocks were rounded on the shore, and sandstone almost filled the gorge where there was once a river. The animal life then consisted of trilobites, oyster like organisms, and other low forms.
The sea retreated and a river once more carried away the material which filled the gap in the bluffs. Because the hills of this region were once buried and again exposed to view, they are sometimes called the "Baraboo fossil."